Improved physical activity (PA) and dietary behaviors and reductions in overweight or obesity show great promise to reduce the risk of type 2 diabetes in adults. However, very few interventions have been reported that address this issue, and none that are useful for primary care providers or that address reducing diabetes risk in adolescents. We propose a randomized controlled trial to evaluate whether an integrated primary care and web-based intervention, PACEi-DP, can produce initial and sustained improvements in anthropometric, behavioral, metabolic, and physiological outcomes in adolescents who meet the ADA criteria for "high risk" for type 2 diabetes. PACEi-DP is a 1- year intervention involving: a) pre-primary care visit web assessment and progress planning; b) clinician counseling; c) 12 months of web-based, phone and/or group-based follow-up. Pilot studies based upon selected elements of PACEi-DP demonstrate its promise in improving dietary & PA behaviors and in stabilizing BMI in overweight adolescents. We will recruit 93 adolescents, age 12 to 16 years, who meet the ADA criteria for high risk of Type 2 diabetes. Subjects will be recruited from 5 healthcare settings and the community and randomly assigned to one of three conditions: 1) usual medical care; 2) a web-based version of PACEi-DP where the follow-up component involves asynchronous web-based contact with subjects and their parent/guardian; or 3) a multi-modal PACEi-DP where the follow-up component adds phone and group contact. PACEi-DP will target 4 behaviors: 1) total energy expenditure from moderate and vigorous PA; 2) sedentary behavior and recreational media use; 3) Fruit/Vegetable/Fiber consumption (5 or more servings/day of fruits/vegetables and 3 or more servings/day of whole grains or legumes); and 4) total fat as percent of energy consumed. The intervention guides patients to select PA & diet target behaviors for which they develop action plans to discuss with the clinician. The clinician endorses or modifies the action plan and encourages participation in the ongoing intervention. Web-tutorials, continuous web access, e-mail interaction, and (in Group 3) phone counseling and group meetings guide patients and parent/guardian to use cognitive & behavioral skills to change behaviors. PACEi-DP enables participants to receive tailored, stage-appropriate intervention on their diet & PA goals. The primary outcome will be the effect of PACEi-DP on BMI at 12 months. Secondary outcomes (at 6 and 12 mo.) will be: a) metabolic and physiological measures of insulin resistance (fasting insulin, fasting blood glucose, blood lipids, microalbuminuria, acanthosis nigricans, and blood pressure; b) anthropometric measures ( percent body fat by DEXA (at 12 months), waist/hip ratios; c) behavioral measures (moderate & vigorous PA; total energy expenditure; CSA; measures of sedentary behavior & recreational media use; servings of fruits, vegetables & fiber; and total fat as a percent of energy consumed. Exploratory measures will include psychosocial mediators of change; measures of parent/guardians' BMI and waist/hip ratios, and process, satisfaction & cost-effectiveness measures of each study arm. The PACEi-DP intervention is particularly innovative because its three components - pre-visit web assessment and behavior change planning, primary care provider counseling, and the ongoing web or web/phone/group intervention -are unified through a common behavioral theoretical framework.